1. Field of the Invention
This invention relates to a tractor scraper vehicle and, more particularly, to an improved construction for the push frame assembly for the scraper bowl and a method of making same.
2. Description of the Prior Art
The push frame for the scraper bowl of a tractor scraper combination has traditionally been a series of subassemblies which are welded and bolted together including a plurality of struts and trusses and various welded reinforcing plates and gussets. In single-engine tractor scrapers, the wheel mounting plates are built into the push frame side rails with the side rails of the push frame being tied together by several cross beams and plates. In double-engine tractor scrapers, a box-like subassembly is mounted between the side rails of the push frame, which structure acts as the differential case, whereby, an engine mounted on the push frame is connected to the differential in the case for driving the wheels attached to axle housings bolted to mounting plates on the box-like subassembly.
The box-like subassemblies have brackets which, in turn, are welded or bolted to the side rails of the framework of the push frame. The connections between the wheel mounting plates and the side rails and between the box-like structure and the brackets and the side rails can become loose or can fail, but, more than likely, because of the tortuous path the loads must follow in passing from the scraper bowl to the side rails, to the brackets, to the mounting plates or box-like structure and to the wheels, twisting, distortion and stress concentrations are produced resulting in structural failures.